Pedestrians or others subject to traffic hazards typically wear one or more high visibility items of apparel. This includes, for example, signalmen standing watch along the side of a road, persons engaged in road construction or maintenance, emergency vehicle personnel, survey crews, law enforcement personnel, and a host of others. This group of individuals is in need of protection from inherent traffic hazards of low visibility regardless of the time of day. These hazards are intensified by the often complex and varying backgrounds found in many occupations subjecting the person to traffic, especially those involving all modes of traffic control, construction, equipment operation and vehicle roadway traffic. The major issue involves situations in which objects are visible but are not consciously recognized by the vehicle operator within sufficient time to take corrective action to avoid an accident.
Various standards have been proposed and adopted addressing the need for high visibility safety apparel to be worn by persons subject to vehicular hazard. For example, various states have adopted standards for safety apparel to be worn by maintenance workers on state highways. Various countries can have their own standards. Such standards typically dictate minimum coverage area and placement of highly reflective material on safety apparel to be worn by the persons subject to the traffic hazards.
Particularly prominent among these standards in the United States are those adopted by the American National Standards Institute which have been published by the Safety Equipment Association in publication ANSI/ISEA 107-1999 entitled American National Standard for High-Visibility Safety Apparel, incorporated herein by reference (the “ANSI Standard”). The ANSI Standard dictates performance requirements for high visibility safety apparel, capable of signaling a user's presence in a conspicuously visible manner under any light conditions by day and under illumination by vehicle headlights in the dark.
Examples of such safety apparel garments are vests, tee shirts, ponchos and waistcoats. The ANSI Standard contemplates that the garment has a background material that is a highly conspicuous colored fluorescent material. This background material will frequently comprise the garment body. The ANSI Standard further contemplates that a retroreflective material be attached to the garment and used in conjunction with the background material. A retroreflective material is one having the ability to return a substantial portion of incident light in the direction of origination of the light.
The ANSI Standard specifies three classes of high visibility safety apparel, according to the intended use of the garment, progressing from class one which is the most lenient, to class three. Class one, for example, includes garments to be worn by delivery vehicle drivers; class two, emergency response personnel; and class three, roadway construction personnel exposed to traffic exceeding 50 mph. For each class, there is specified for the garment a minimum surface area of background material, and a minimum surface area on the garment of retroreflective material. The current requirements are shown below:
Class:123Background material2177751240exposed (square inches)Retroreflective material155201310exposed (square inches)
For all classes, the Standard requires that torso covering garments have a contiguous area of retroreflective material encircling the torso placed in such a manner to provide 360° visibility of the wearer. This is commonly interpreted to refer to a horizontal band or stripe encircling the torso having a minimum width of 50 mm for a class 3 garment, and 35 mm for a class two garment. A similar requirement applies to sleeves and trouser legs.
In addition, the ANSI Standard has a specification for the photometric performance of the retroreflective material. This is a measure of the efficiency of the retroreflective material in returning light to its source. It is expressed in terms of a coefficient of retroreflection (R).
The conventional approach to providing safety apparel with adequate visibility both before and after ANSI Standard's inception, and continuing to be used to meet the ANSI Standard, is to apply a continuous solid stripe of retroreflective material to the garment. Such a continuous stripe imparts an undesirable measure of rigidity to the garment. The retroreflective material does not bend as readily as the underlying fabric. This gives the garment a stiff look and feel. A solid stripe impedes heat loss from the body of the wearer of the garment. This is a comfort consideration in warm weather.